Monday Poster Sessions, October 29, 2006
HCV Therapy: Pre-clinical and Early Clinical Development
M. Rodriguez-Torres; E. Lawitz; A. Muir; J. Keane; T. Kieffer;
L. McNair; J. G. McHutchison
Purpose:
Telaprevir (VX-950)
is an orally administered, highly selective peptidomimetic
inhibitor of the Hepatitis C virus (HCV) NS3-4A protease. In previously
reported Phase 1b studies, telaprevir was well
tolerated alone and with peginterferon-alfa-2a (Peg-IFN) for 14 days, and the
marked antiviral effects of telaprevir are increased
with the addition of Peg-IFN. This study was designed to assess the safety of telaprevir when given in combination with Peg-IFN and
ribavirin (RBV) and to evaluate the antiviral response during 28 days of
dosing. Here we report patient status during ongoing post-study follow-on
therapy.
Methods:
The VX05-950-102 clinical study
included 12 treatment-naïve patients infected with genotype 1. All subjects
received telaprevir (750 mg q8h), Peg-IFN (180 µg
weekly), and RBV (1000 or 1200 mg daily). At the completion of the 28 days,
patients began off-study follow-on standard therapy with Peg-IFN/RBV.
Results:
At 24 weeks after the start of
Peg-IFN-2a/RBV:
·
9 subjects had undetectable HCV RNA
·
2 subjects had detectable HCV RNA
·
1 subject was lost to follow-up
Conclusions:
·
2/12
subjects had detectable HCV RNA at the end of the study dosing and continued
Peg-IFN-2a/RBV therapy
·
9/11
subjects treated initially with telaprevir in
combination with Peg-IFN-2a and RBV who continued Peg-IFN-2a/RBV, maintained
undetectable HCV RNA through week 24 in the off-study Peg-IFN/RBV treatment
period.
o
one
subject lost to follow-up
·
Viral
sequencing suggests that:
o
Variants
are detected transiently early in treatment but remained undetectable during
follow-on treatment
o
In
the 2 patients with breakthrough, detection of both WT and R155K suggest that
breakthrough may be related to a poor response to Peg-IFN-2a/RBV
o
It
will be important to evaluate longer durations of telaprevir
treatment
·
The
safety and efficacy of a telaprevir-based treatment
in longer regimens is currently being evaluated in Phase 2 studies (PROVE1 AND
PROVE2).
W.
Jiang; S. Chiu; S. Ali; M. Chapman; C. Daniel; T. Kretz; N. Cammack; J. Symons; K. Klumpp
Introduction:
R1479 (4’-azido-cytidine) is a
potent, specific inhibitor of the HCV subgenomic
replicon replication by targeting HCV polymerase mediated RNA synthesis. R1626,
a prodrug of R1479, has shown promising anti-HCV activity in a Phase I clinical
study in chronically HCV infected patients. Future clinical studies will assess
safety and efficacy of R1626 in combination with other antiviral agents.
Results:
In the present study, we
investigated the in vitro antiviral interactions of R1479 with other HCV
replication inhibitors using the HCV subgenomic
replicon system. Huh-7 cells containing HCV replicon were treated with a dose
range of R1479 in a checkerboard, pair-wise manner with a dose range of either
IFN α-2a, ribavirin, 2’-fluoro-2’-C-methylcytidine (PSI-6130),
2’-C-methylcytidine (NM107), the non-nucleoside inhibitors thiophene–2
carboxylic acid and benzo-1,2,4-thiadiazine, and the macrocyclic
tripeptide HCV serine protease inhibitor (BILN2061).
The antiviral interaction of each drug-combination was assessed using a
three-dimensional response surface approach based on the Bliss independence
theory (MacSynergy II) or the Greco model based on
the Loewe additivity
theory. Analysis using both models indicated that R1479 exerted moderate
synergistic effects when combined with either IFN α-2a or ribavirin with
no associated increase in cellular toxicity.
Conclusions:
Combinations of R1479 with other
HCV Polymerase inhibitors PS1-6130, 2’-C-Me-C, a palm-binding NM1, and a HCV
serine protease BILN 2061 demonstrated additive effects. No antagonistic
effects were observed with any of the combinations within the range of
concentrations tested.
V.
Goossens; I. Borghmans; A. Schittecatte; A. Van der Aa; G. Verheyden; S. Southwood; C. Dahlberg; D. McKinney; M. Newman; J. Pletinckx; I. Lasters; J. Desmet; G. Maertens; M. Buyse
Background:
Successful viral clearance has been
shown to be associated with strong and multispecific
CD8+ T-cell responses accompanied by strong CD4+ T-cell responses. A candidate polyepitope therapeutic T-cell vaccine that is able to
induce both potent CD8+ and CD4+ specific T-cell responses could ultimately
lead to viral clearance. Such a vaccine should be applicable to the majority of
infections, taking human HLA as well as HCV genotype diversity into account.
Methods:
HCV-derived CTL epitopes
for the most prominent HLA-A, -B, and -C alleles were identified using
algorithms developed by Pharmexa-Epimmune (San Diego,
CA), Algonomics (Ghent, Belgium), and publicly
available algorithms. Further selection was made based on in vitro binding
affinity of the peptides. A subset of good binders was further evaluated for immunogenicity in human HLA transgenic mice. A single
immunization with CTL peptide pools, together with the common PADRE HTL epitope emulsified in IFA, was performed and 14 days later,
CD8+ spleen cells were isolated and evaluated for peptide specificity using a
direct ex-vivo IFNγ ELISPOT. In parallel,
predicted HCV-derived HTL epitopes were evaluated for
their in vitro binding to different DRB1* alleles and for their immunogenicity in DRB1*0401 transgenic mice.
Results and discussion:
Several medium (Ki
or IC50 <500 nM) and high (Ki
or IC50 < 50 nM) affinity binding peptides were
identified for all selected HLA -A, -B and -C alleles. Cross-reactivity to
different HLA loci was demonstrated for some of the peptides.
Peptides binding to HLA A*0201, A*1101,
A*2402 or B*0702 alleles with medium or high affinity were selected for
evaluation of CTL induction in the respective HLA transgenic mice. Based on IFNγ ELISPOT several highly immunogenic epitopes were identified. Similarly, a set of HTL epitopes was identified showing promiscuous binding to the
DRB1* alleles. Immunogenicity testing in DRB1*0401
transgenic mice revealed that in vitro affinity was a strong predictor of
significant immunological responses. Population coverage calculations showed
that the selected set of CTL and HTL epitopes could
provide recognition of at least 4 CTL and 3 HTL epitopes
in an HCV genotype 1-infected subject irrespective of HLA type.
Conclusion:
A pool of HCV-derived CTL and HTL epitopes were identified that show excellent affinity and immunogenicity. Based on the HLA and HCV genotype
cross-reactivity, more than 45 epitopes were selected
that could form the basis for the development of a universal T-cell vaccine
candidate for HCV.
S.
T. Shi; K. J. Herlihy; J. Gonzalez; A. K. Patick; R. Duggal
Discussion:
A novel class of nonnucleoside HCV polymerase inhibitors characterized by a dihydropyrone core was identified by high throughput
screening. Crystallographical studies of these
compounds in complex with the polymerase identified an allosteric
binding site close to the junction of the thumb and finger domains,
approximately 30 Å away from the enzyme’s catalytic center. AG-021541, a
representative compound from this series, displayed measurable in vitro
antiviral activity against the HCV subgenomic
replicon with a mean EC50 value of 2.9 µM. To identify mutations conferring in
vitro resistance to AG-021541, resistance selection was carried out using HCV
replicon cells harboring a genotype 1b subgenomic reporter replicon either by serial passages in
increasing concentrations of AG-021541 or by direct colony formation at fixed
concentrations of the compound. Both population and clonal
sequencing were performed to identify genotypic changes in AG-021541-resistant
cell lines. We identified several amino acid substitutions in the
inhibitor-binding region of the polymerase, including M423T, M423V, and V494A.
The most predominant mutation, M423T, conferred an 87-fold reduction in
susceptibility to AG-021541 but no change in susceptibility to interferon.
AG-021541-resistance replicon cell lines provide a valuable tool for
specificity and mechanism of action studies of dihydropyrone
polymerase inhibitors. The clinical relevance of in vitro resistance to HCV
polymerase inhibitors remains to be investigated.
Conclusions:
·
In vitro resistance studies of AG 021541 by either
passages or instant colony formation using the replicon cells identified amino
acid changes at the thumb-base allosteric site
·
The most predominant mutation, M423T, conferred an
87-fold reduction in susceptibility to AG-021541, but no change in
susceptibility to IFN
·
Introduction of M423T, M423V or V494A into the
wild-type replicon resulted in reduction replication fitness and resistance to
AG-021541 and structurally related to compounds
·
In vitro resistance studies are useful tools for
determining the specificity and target/MOA of anti-HCV compounds.
·
Resistance mutations identified in the replication
system may have future clinical implications.
932. Assessment of the Pharmacological Activity of PEGylated Recombinant Interleukin-29 (PEG-rIL-29) in Cynomolgus Monkeys.
J.
A. Freeman; J. Heffernan; K. Klucher; P. Sivakumar; S. Pederson; J. Visich;
P. Rafael; M. Rogge
Background:
Interleukin-29 belongs to a family
of Class II cytokines and binds to a heterodimeric
receptor consisting of the unique IL-28R alpha chain and the common IL-10R beta
chain. Binding of IL-29 to this receptor activates the JAK/STAT pathway in a
similar fashion to interferon alpha, and has been shown to induce intracellular
antiviral responses in vitro. The Type I interferon receptor is expressed by a
wide variety of cell types; however, the IL-29 receptor is expressed by only a
subset of these cell types. We have investigated whether the differences in the
pattern of receptor expression result in pharmacological differences between
interferon alpha and IL-29.
Methods:
The in vivo activity of a PEGylated form of IL-29 (PEG-rIL-29) was evaluated in cynomolgus monkeys. Pharmacological responses were assessed
following either a single or three (every-other day dosing) intravenous doses
of 0.03, 0.3, or 3.0 mg/kg PEG-rIL-29. As controls, monkeys were also dosed
with vehicle or 1x107 IU/kg interferon alpha 2a. In vivo response to dosing
were assessed by quantifying changes in circulating neopterin,
2’5’-oligoadenylate synthetase (OAS) activity, and
beta-2 microglobulin. Responses were also assessed by
analyzing changes in the expression of the interferon-stimulated genes, MxA and PkR, and in OAS activity
within peripheral blood leukocytes (PBLs) and liver
biopsy samples.
Results:
Dosing with PEG-rIL-29 resulted in an
induction in the expression of MxA and PkR in liver biopsy samples taken four hours after dosing,
and in an elevation in intracellular OAS activity in liver biopsy samples taken
48 hours after dosing. A similar induction of these markers was observed across
all dose levels. Furthermore, the induction of these markers by PEG-rIL-29 was
largely equivalent to that by interferon alpha. Consistent with the
differential expression pattern of the IL-29 receptor, MxA
and PkR expression and OAS activity was induced in PBLs by interferon alpha but not by PEG-rIL-29. Similarly,
plasma OAS, serum neopterin, and serum beta-2 microglobulin were elevated by interferon alpha, whereas
only serum beta-2 microglobulin was induced by
PEG-rIL-29.
Conclusions:
·
Localization of PEG-rlL-29 activity appears to be
more restricted than that of IFN-a
·
No overt changes in measured immunological
parameters observed following dosing with PEG-rlL-29
·
Serum B2M is a relevant circulating marker of
PEG-rlL-29 activity that may be monitored in subsequent nonclinical
studies
H.
Tan; S. D. Seiwert; L. M. Blatt
Purpose:
ITMN-191 is a highly potent, orally
absorbed inhibitor of the NS3/4A protease that accumulates in the liver of rats
and cynomolgus monkeys at levels suggestive of human
efficacy. This compound is currently undergoing preclinical development. The
objective of this study was to evaluate the in vitro antiviral activity of
ITMN-191 in combination with peginterferon alfa-2a
(PEG-IFN alfa-2a).
Methods:
Two replicon systems were used for
anti-HCV drug-drug interaction study: an HCV genotype-1b replicon (K2040) and a
derivative of K2040 with reduced sensitivity to ITMN-191 (R191M320). Drug-drug
interaction data were analyzed by the Loewe additivity model and the Bliss independence drug
interaction model.
Results:
The combination of ITMN-191 and
PEG-IFN alfa-2a synergistically inhibited HCV RNA replication in Huh7 cells.
Analysis of fixed dose ratios by the Loewe additivity model showed that combination of the two drugs
yielded combination index (CI) values indicative of synergy at EC50, EC75 and
EC90 (0.3, 0.4 and 0.4, respectively) and isobologram
analysis supported synergistic interaction. The drug reduction index (DRI)
values were >1, suggesting a potential clinical benefit when ITMN-191 is
administered in combination with PEG-IFN alfa-2a. Analysis of variable ratio
drug combinations by the Bliss independence model indicated that the synergy
volumes observed in ITMN-191 combinations were significant (>50 uM2). Peak
synergy volumes occurred at low concentrations, all of which may be
therapeutically relevant. The extent of synergy observed by either method is
quantitatively larger than that observed for the experimental HCV protease
inhibitors VX-950 and SCH 503034. Importantly, the human minimum plasma
concentration (Cmin) of PEG-IFN alfa-2a greatly
improved ITMN-191 potency in a replicon fully sensitive to ITMN-191 and in a
replicon with reduced sensitivity to ITMN-191. Additionally, the replicon with
reduced sensitivity to ITMN-191 was hypersensitive to PEG-IFN alfa-2a relative
to the parental replicon (>10 fold).
Conclusions:
·
ITMN-191 and Peg-INF-a-2a demonstrated strong
antiviral synergy by multiple analyses
·
When used in combination, reduced doses of both
agents produce antiviral effects similar higher doses of each agent when used
individually
·
At its minimal plasma concentration, Peg-IFN-a-2a
greatly enhances the potency of ITMN-191
·
Clinical exploration of the combined antiviral
effects of these two agents is warranted
D.
R. HOUCK; S. Hopkins
Background:
Cyclosporine A (CsA)
is known to inhibit HCV replication in vitro and appears to have a therapeutic
effect on clinical HCV infection. Recent studies indicate that it acts through
inhibition of the human protein cyclophilin. CsA and other members of this natural product family cannot
be used as antiviral therapeutics because they have narrow therapeutic indexes
due to dose limiting immune, renal and cardiovascular toxicities. In this work
we evaluated a non-immunosuppressive cyclophilin
inhibitor, SCY-635, as potential clinical candidate for anti-HCV therapy.
Methods:
SCY-635 was evaluated for antiviral
activity, cytotoxicity, immunosuppression,
cyclophilin inhibition, and bioavailability. The
compound was tested in the HCV Replicon in Huh7 cells and against BVDV in MDBK
cells. Immunosuppression and cyclophilin
inhibition were determined in murine-mixed-lymphocyte
reaction (MLR) and peptidyl-prolyl-isomerase
inhibition assay, respectively. In vitro ADME properties such as microsomal stability were also examined. Pharmacokinetic
parameters were determined after single dose in monkeys.
Results:
Compared to cyclosporin,
SCY-635 had potent (2 nM)affinity for cyclophilin A, 2) had improved anti-HCV activity, 3) was
>100-fold less active in the MLR, and 4) was less cytotoxic.
Using both the luciferase and RNA endpoints, SCY-635
potently inhibited HCV replication in replicon cells. There was a
dose-dependent reduction of HCV RNA at 24, 48, 72 and 120 h incubation periods.
Drug-combination experiments demonstrate that SCY-635 is additive to
synergistic with IFN-α in the replicon cells. SCY-635 also inhibited the
viral replication in the BVDV assay. SCY-635 is much-more slowly metabolized in
human microsomes than cyclosporin
A. In vivo pharmacokinetic studies demonstrate approximately 50%
bioavailability, providing blood levels of drug well in excess of the in vitro
IC50 for HCV replicon.
Conclusion:
·
SCY-635, a soluble analog of CsA,
binds and inhibits cyclophilin A and cyclophilin B
·
SCY-635 suppresses in vitro HCV replication by
>95% at sub-µM concentrations
·
Pharmacokinetic data demonstrate that SCY-635
concentrations are well above the antiviral IC90
·
In vitro drug-combination studies suggest SCY-635 is
compatible for use with IFN- and ribavirin
·
SCY-635 is a clinical candidate for therapy of HCV
infected patients
S.
S. Carroll; M. Davies; L. Handt; K. Koeplinger; R. Zhang; S. Ludmerer;
M. MacCoss; D. Hazuda; D.
Olsen
Purpose:
to evaluate the antiviral efficacy
of administration of a nucleoside polymerase inhibitor to hepatitis C virus
(HCV) infected chimpanzees.
Purpose:
to evaluate the antiviral efficacy
of administration of a nucleoside polymerase inhibitor to hepatitis C virus
(HCV) infected chimpanzees.
Background:
Efforts to develop novel therapies to
treat HCV infection that enhance both efficacy and tolerability over existing
therapies have focused on direct antiviral agents targeting the virally encoded
RNA-dependent RNA polymerase, NS5B, and protease, NS3/4A. Previously, we have
shown that a nucleoside analog inhibitor of the NS5B RNA polymerase potently
inhibits HCV RNA replication in the bicistronic
replicon assay with an EC50 of 0.3 micromolar.
Methods:
The nucleoside analog was
administered once daily to chronically infected chimpanzees by either oral or
intravenous routes at different dose levels, and for different durations.
Periodically blood samples were withdrawn, and plasma viral titers
were determined using the Versant bDNA (Bayer), HCV Taqman
(Roche), or transcription mediated amplification (Bayer) assays.
Results:
The nucleoside analog can
profoundly suppress viral replication in chimpanzees chronically infected with
HCV. Once daily administration of the compound resulted in a rapid,
dose-dependent decrease in plasma viral RNA. At the highest dose evaluated,
viral RNA levels in plasma decreased during dosing to levels below the limit of
quantitation of the Taqman
assay, representing a ≥5 log decrease in plasma viremia. Longer term
dosing resulted in substantial decreases in viral load and no rebound during
dosing was evident.
Conclusions:
·
IV
and oral dosing of 7-Deaza-2’-C-methyl-adenosine to HCV-infected chimpanzees
result in significant reductions in viral load.
o
>5
log reduction in viral load (2 mpk IV)
o
No
rebound during dosing
o
Delay
in rebound after end of extended dosing
·
Resistant
viral variants at S282 are detected after dosing ends as virus starts to
rebound
o
Variants
not detected in samples from later time
N.
Kamiya; E. Iwao; N. Hiraga; M. Imamura; S. Takahashi; K. Chayama
Discussion:
As a small animal model for
hepatitis C virus (HCV) infection, several teams are investigating homozygous urokinase plasminogen activator (uPA)-SCID mice transplanted with human hepatocytes. This
model is expected to contribute to the evaluation of antiviral therapy whereas
there has been less information about viral kinetics under a drug treatment.
Using more than thirty uPA-SCID mice where more than half of the liver was
repopulated by human hepatocytes, we investigated viral kinetics in this animal
model treated with the HCV NS3-4A protease inhibitors, MP-424/VX-950 and BILN 2061.
Repopulation index of human hepatocyte in the liver from an uPA-SCID
mouse was estimated by human serum albumin (hAlb)
concentration in blood. After intravenous infection with HCV genotype 1b, high
viral load (>106 copies/mL) was achieved among most animals and plateaued within 6 weeks. The viremia persisted throughout
their lives in most animals up to 28 weeks. After the infection, hAlb titer tended to decline
slightly and slowly and some positive correlation with HCV titer
in serum could be observed especially in a later phase. Oral administration of
the HCV NS3-4A protease inhibitors could reduce viral load in this mouse model,
and the titer restituted
after withdrawal of the drugs. Therefore, the same animals were used to
evaluate a different regimen for several independent periods. In the
preliminary experiment, twice daily administration of MP-424/VX-950 formulation
for 7 days resulted in about half log10 decrease in HCV load, while the same
animals re-treated with it three times daily for 3 days showed nearly 1 log10
decrease. This result might suggest the importance of maintaining trough
concentration of the drug to show the efficacy in this mouse model. When
sufficient trough concentration of MP-424/VX-950 could be achieved, rapid and
linear log decrease in HCV RNA titer in serum was
observed within the first 12 hrs (≈2 log10) and the mean slope was
estimated as 0.15 log10 copies/hr, which might be equivalent to the rate of
initial phase decline observed in hepatitis C genotype 1 patients treated with
VX-950/MP-424. When MP-424/VX-950 improved formulation or BILN 2061 in solution
was administrated orally twice daily, 2-3 log10 reduction of viral load was
also observed within 2 days. VX-950/MP-424 and BILN 2061 were demonstrated high
and very rapid reduction in serum viral load in their proof-of-concept clinical
studies.
Conclusion
·
MP-424 suppressed the
replication of IFN-NR-derived HCV genotype 1b virus production in vivo in chimeric SCID-uPA mice
·
An early and rapid
reduction in viral load was observed in the SCID-UpA
mouse model, similar to that observed in humans
·
Using elder mice with
high viral, bi- and tri-phasic clearance patterns
could be observed, similar to what has been observed in humans
W.
Yang; Y. Zhao; J. Fabrycki; X. Hou;
X. Nie; Y. Sun; A. Phadke;
A. Agarwal; M. Deshpande;
M. Huang
Background and aims:
We have discovered a novel class
of compounds active against HCV. The lead compound in the series, ACH-806, is a
potent and specific inhibitor of HCV. Mechanism of action studies revealed that
inhibition of HCV occurs via blocking of functional replication complex formation.
Resistance induction studies were conducted to identify the target of these
novel inhibitors, and to determine cross- resistance profile with other classes
of inhibitors.
Methods and results:
Resistance induction studies were
performed using compounds in ACH-806 series. Several clones emerged after
addition of the inhibitor and G418 to Huh-7 cells containing stably transfected HCV replicon at frequency and duration similar
to that observed with other classes of HCV specific inhibitors. Phenotypic
analysis of these clones revealed that: 1) They are resistant to their inducing
agents and to their analogs; 2) They remain sensitive to other classes of HCV
inhibitors; 3) Resistant phenotype is relatively stable and 4) Resistance is
due to adaptation in the viral genome. Sequencing of the entire coding region
of resistant clones yielded several consensus mutations. Reverse genetics
identified a single mutation located at the very N-terminus of NS3 that is
responsible for resistance. We also conducted resistance induction studies with
a NS3/4A protease inhibitor, NS5B nucleoside inhibitor and nonnucleoside
inhibitor. As expected, resistant clones obtained with protease or polymerase
inhibitors are resistant to their inducing agents, but remain sensitive to the
compounds in ACH-806 series. Lack of cross resistance between ACH inhibitors
and protease or polymerase inhibitors is explained by genotypic analysis of
resistant clones.
Conclusions:
·
HCV variants resistant to the compounds in ACH-806
series were obtained. These resistant variants carry novel mutation(s) and are
not cross- resistant to other classes of HCV inhibitors.
·
ACH-806 is a novel and potent inhibitor of HCV
·
Resistance mutations to ACH-806 are mapped to the
very N-terminus of NS3 protein
·
ACH-806 is not cross resistant with other classes
of HCV inhibitors
LB2. Results of a Phase 1B, Multiple Dose Study of R1626, a Novel Nucleoside Analog Targeting HCV Polymerase in Chronic HCV Genotype 1 Patients.
S. Roberts; G. Cooksley; G. Dore; R. Robson; D. Shaw; H. Berns;
M. Brandl; S. Fettner; G.
Hill; D. Ipe; K. Klumpp; M.
Mannino; E. O'Mara; Y. Tu;
C. Washington.
Background and Aims:
HCV polymerase, an essential enzyme for HCV replication, is a
promising target for the development of compounds to treat HCV infection.
R1626, is a prodrug of the nucleoside analog R1479, a potent inhibitor of HCV
replication in vitro. This multiple ascending dose study was designed to
evaluate the safety, tolerability, pharmacokinetics, and antiviral activity of
R1479 in previously untreated patients with chronic HCV genotype-1 infection.
Methods:
Patients were treated for 14 days with R1626 and followed up
for another 14 days. Assessments included safety, PK, and antiviral activity
measured as serum HCV RNA levels.
Results:
A total of 47 patients were randomized to oral treatment with
500 mg, 1500 mg, 3000 mg or 4500 mg of R1626 or placebo twice daily. The mean
viral concentrations at baseline were ≥ 6.5 log10 IU/mL in all
four cohorts. Following oral administration, R1626 was efficiently converted to
R1479 with dose proportional pharmacokinetics observed over the entire dose
range. Dose and time dependent mean (median) viral concentration decreases of
1.2 (0.8), 2.6 (2.7) and 3.7 (4.1) log10 were observed at 1500, 3000 and 4500
mg, respectively. R1626 was generally well tolerated with increasing adverse
events at the highest dose (4500 mg). No viral resistance was found. Reversible
mild to moderate hematological changes were observed
with increasing doses.
Conclusions:
R1626 is a novel nucleoside analog targeting HCV polymerase.
These data demonstrate that R1626 is capable of significantly reducing HCV RNA
in monotherapy. The decreases in HCV RNA from baseline observed with R1626 are
greater than those previously described for HCV polymerase inhibitors and
similar to those seen with protease inhibitors. These promising results warrant
further investigation of R1626 in combination treatment.
G.
T. Everson; M. J. Tong; I. M. Jacobson; D. M. Jensen; A. A. Haller; G. M.
Lauer; J. Parker; J. Ferraro; S. E. Cruickshank; R. C. Duke; D. Apelian; T. C. Rodell; E. R.
Schiff
Purpose
Tarmogens (targeted
molecular immunogens) are whole, heat-killed
recombinant S. cereviside yeast engineered to express
one or more target protein antigens. Tarmogens activate both an innate immune response via
Toll-like receptors (TLRs), as well as an adaptive,
antigen specific cellular immune response.
GI-5005 was engineered to express a hepatitis C virus (HCV) fusion
protein comprised of large segments of NS3 protease and Core protein
sequences. These proteins were chosen as
targets for ummunotherapy because they are essential
for viral replication, contain multiple epitopes that
are receognized by both Helper T cells (CD4+) and Killer
T cells (CD8+) in acute and chronic HCV infections, and are highly conserved
among the different HCV genotypes.
GI-5005, by expressing multiple antigens, was designed to induce a broad
cellular immune response, comparable to that which as has been associated with
sustained viral clearance in patients acutely exposed to HCV>
In preclinical studies, GI5005 has
demonstrated:
1.
The ability to induce potent HCV-specific killer T
cell and helper T cell responses;
2.
Dose dependency of response, which s boosted with
repeat injections;
3.
No evidence of immune neutralization or immune
tolerance with repeated injections;
4.
In non-clinical safety studies, GI-5005 and other
comparable Tarmogens for infectious disease targets
and cancer have been administered to a number of species including mice, rats,
rabbits, and non-human primates in both live and heat-killed forms and no
significant systemic toxicity has been observed.
GI-5005-01 was initiated to
evaluate the subcutaneous administration of six dose levels of GI-5005 vs.
placebo in subjects with chronic hepatitis C infection who were either partial
responders or relapsers to an interferon based regimen using either pegylated
or non-pegylated interferon alpha with or without ribavirin, or are treatment
naïve due to a contra-indication or refusal to take interferon based
therapy. This is an interim analysis
describing the results from 40 patients (0f 72) enrolled in the first four
dose-cohorts.
Methods
GI-5005 is whole heat-killed S. cerevisiae yeast harboring HCV NS3
and Core antigens. Subjects with chronic hepatitis C infection who were
interferon (IFN) relapsers, partial responders or treatment naïve were
eligible. IFN “null responders” and patients with cirrhosis were ineligible.
Treatment consisted of 5 weekly subcutaneous (SC) doses of GI-5005 (0.05YU) or
placebo over 29 days, followed by two monthly SC doses, and 9 months of
post-treatment follow-up. Sequential dose groups of 0.05, 0.5, 2.5, 10YU
(1YU=107 yeast) were randomized 3:1 treated:placebo.
Results
Safety Summary
There were no serious adverse
events, dosing limiting toxicities, or discontinuations due to adverse
events. Related non-serous adverse
events were generally limited to transient local injection site tenderness, swelling,
and redness consistent with delayed type hypersensitivity, and mild
constitutional complaints such as fatigue and low grade fever.
HCV RNA
To date in this study, three
treated subjects had near-log 10 reductions in viral load (0.75-0.09
log 10 ). 2/3 of these subjects demonstrated positive ELISpot results (profiles 014 and 007 to the left); testing for the third is ongoing. No subjects treated with placebo had viral
load reductions in this range. Mean
change in serum HCV RNA was comparable between treated and placebo subjects.
Hepatic Injury
ALT is well validated measure of
hepatic injury and serves as a surrogate for hepatic inflammation. In prior large hepatitis trials, reductions
and/or normalization of ALT levels have been shown to correlate with improved
hepatic inflammation and fibrosis as determined by serial biopsy. In the lowest four dose cohorts, there was a
statistically significant difference in maximum ALT reduction (p=0.03) in
treated subject versus placebo.
Evaluation of the first 4 cohorts
has not revealed a definitive association of response with dose for biochemical
as well as immune or viral load endpoints.
Upcoming treatment and evaluation of 20YU and 40YU dose groups will
enable further exploration of potential dose response for these key endpoints.
Conclusion
1.
GI-5005 is well tolerated with no SAEs, no DLTs, and no
discontinuations due to AEs observed to date.
2.
GI-5005 converted subjects with a weak cellular
immune response typical of chronic HCV patients to a strong cellular immune
response with broad HCV epitope coverage, consistent
with the immune response seen in patients during the acute stage of infection
3.
The immune responses were observed in association
with favourable changes in viral load and ALT:
a.
A statistically significant difference in maximum
change in ALT from baseline to all GI-5005 treated subjects compared to placebo
treated subjects (p=0.03)
b.
Three treated subjects had viral load reductions
approaching 1 log 10 (.075
log 10 –0.09 log 10);
no placebo subjects had HCV RNA reductions >0.065 log10
4.
For immune therapies, HCV viral load reductions may
be a trailing indicator of response, following early improvement in biochemical
and immune markers.
This research was supported by GlobeImmune,
Inc.
G. Pelletier; I. Stucker; G.
N'Kontchou; M. Loriot; S. Cenee; M. Gelu-Simeon; F. Degos; P. Beaune; P. Laurent-Puig; J. Trinchet
Introduction
It has been recently suggested that coffee drinking decreases
the risk of chronic liver diseases (Ruhl et al, Gastroenterology 2005). We performed in
France a case control study to look for predisposing risk factors of
hepatocellular carcinoma (HCC). The data that we present here aimed at analyse
the coffee consumption among HCC cases, cirrhosis patients and controls without
liver disease.
Methods:
The study is an epidemiologic hospital based case control
study. Cases (n=134) were newly diagnosed patients as primary HCC developed on
cirrhotic liver (alcoholic 62 %, viral 24 %), on the basis of either histology
or the presence of focalized lesions detected by any imaging technique,
combined with an alpha feto-protein (AFP) level >
250 ng/ml. Cirrhosis (n=122-alcoholic 79 %, viral 15
%) were defined either by histology or by the combination of clinical,
laboratory, and endoscopic signs. The absence of HCC was established by the
absence of focalized lesions by imaging techniques and by a AFP level < 10 ng/ml. Controls included hospital patients without any
liver disorder (n=142).
All subjects were male, aged less than 75 years, born in
Europe of parents born in Europe. The three groups were matched for age and
birth country. HCC and cirrhosis patients were supplementary matched for time
since cirrhosis diagnosis. Cases and controls were interviewed with a food
frequency questionnaire that included lifetime drinking habits (ie alcohol, soft drinks, coffee, tea consumption). Coffee
consumption was categorized as < 1 cup, 1 to 2 cups, > 2 cups/day. Blood
samples were collected on EDTA and a DNA bank was established for all subjects.
Results:
As shown in the table, we observed a significantly higher
coffee consumption among controls without liver disease as compared to HCC
cases (p < 0.01), whereas there was no differences between cirrhotic
patients with or without HCC. All these associations were adjusted for alcohol
consumption considered in drink/day.
Conclusion:
Our study confirms that coffee consumption may decrease the
risk of chronic liver diseases, but suggests that coffee does not decrease the
risk of HCC in cirrhotic patients.
|
Coffee |
Controls
|
Cirrhosis
|
OR(IC) |
HCC |
OR(IC) vs controls |
|
0-1 |
40 % |
56 % |
1 |
56 % |
1 |
|
2 |
26 % |
24 % |
0.65 |
27 % |
0.67 |
|
>2 |
34 % |
20 % |
0.33 |
17 % |
0.36 |
|
m + sd |
2.4 + 2.1 |
1.8 + 1.9 |
|
1.8 + 1.6 |
|
LB23. Rapid and Early Virologic Responses to Peginterferon Alfa-2a plus Ribavirin in Treatment-Naïve Latino vs non-Latino Caucasians Infected with HCV Genotype 1: the LATINO Study.
M.
Rodriguez-Torres; V. Ankoma-Sey; M. Y. Sheikh; L. Rossaro; F. M. Hamzeh; L. J.
Jeffers; L.
Introduction
Latinos have been under-represented in clinical trials of CHC
and undertreated in clinical practice. To date, there
have been no prospective studies evaluating the response rate of Latino
Caucasians to HCV therapy. The LATINO Study was designed to compare the
responses of Latino and non-Latino Caucasians infected with HCV genotype 1 to
treatment with peginterferon alfa-2a and ribavirin.
Methods
This was a prospective, multi-center, open label,
comparative, efficacy study designed to treat 267 Latino and 302 non-Latino
Caucasian patients infected with HCV genotype 1 and naïve to treatment; the
number of cirrhotic patients in each group was 34 (12.7%) Latino group and 29
(9.6%) in the non-Latino Caucasian group.
Country of origin was documented for Latino patients—Mexico (51%),
Puerto Rico (32%), Cuba (9%), other (8) and 1% as Mexican and unknown
(1%). Baseline characteristics were
generally well matched. The Latino group was slightly younger (45.5±8.83 y vs 48.1±8.31 y) and had slightly higher BMI (29.8±5.69
kg/m2 vs 27.9±5.43 kg/m2), slightly lower mean log
[HCV RNA] (6.3±0.05 vs 6.4±0.04).
All patients were treated with 180 μg/week
peginterferon alfa-2a plus 1000 or 1200 mg/d
ribavirin for 48 weeks. HCV RNA was quantified using the Roche High Pure
System/COBAS TaqMan HCV Monitor Test, which has a
lower limit of detection (10 IU/mL) and a broader linear range for
quantification (30-200 million IU/mL) than standard PCR tests. This interim
analysis shows rapid virologic response (RVR) and early virologic response
(EVR) rates in the two groups of patients.
Results
Interim results showed that 195/247 Latinos (78.9%) and
248/279 non-Latinos (88.9%) attained EVR, defined as a ≥2 log [HCV RNA]
drop from baseline or undetectable (<10 IU/mL) HCV RNA at Week 12.
Undetectable HCV RNA was attained by 35/261 Latinos (13.4%) and 53/293
non-Latinos (18.1%) at Week 4 and by 121/247 (49.0%) and 182/279 (62.5%),
respectively, at Week 12. Through Week 12, 5 Latinos (1.9%) and 12 non-Latinos (4.0%)
withdrew due to adverse events, and 15 (5.6%) and 13 (4.3%), respectively,
withdrew for non-safety reasons.
Conclusion
The interim results showed that RVR and EVR rates were higher
in non-Latino Caucasians than in Latino Caucasians. Combination therapy was
safe in both populations. This ongoing trial will show if this trend holds over
the long term and if SVR rates differ.
E.
K. Kuffner; A. R. Temple; K. M. Cooper; J. S. Baggish; D. L. Parenti
Background:
In some osteoarthritis studies where
acetaminophen (APAP) was administered over multiple days, low-level alanine
aminotransferase (ALT) elevations have occasionally been reported.
Objective:
To retrospectively analyze ALT
data from McNeil-sponsored osteoarthritis clinical studies to assess the
frequency and magnitude of ALT elevations and the rate of ALT resolution while
continuing treatment with the maximum recommended daily dose of APAP.
Methods:
Nine controlled osteoarthritis
clinical trials were identified in which APAP alone was administered in at
least 1 treatment group. Baseline and on-treatment ALT values were measured in
7 studies. Patients receiving the maximum recommended daily dose of APAP (3900
or 4000 mg/day) for 4 weeks to up to 12 months were included.
Results:
No patient treated with the
maximum recommended daily dose of APAP developed hepatotoxicity or hepatic
failure. In the 7 studies, 892 patients had baseline transaminase
activity at or below the upper limit of the reference range (ULRR), had an
on-treatment ALT measurement, and received the maximum recommended daily dose
of APAP. While taking the maximum recommended daily dose, 733 (82.2%) of 892
patients never had an ALT above ULRR.
Of the 892 patients, 42 (4.7%) had
an on-treatment ALT >1.5 times ULRR (Table). A subsequent ALT value
following the elevation was available for 29 of these 42 patients. Documented
resolution or a decreasing ALT while continuing APAP treatment was noted for 27
patients (93.1%). No patient had an on-treatment ALT >3 times ULRR in conjunction
with hyperbilirubinemia. No patient had an ALT >10 times ULRR. An ALT above
ULRR was not associated with an increased frequency of symptoms potentially
related to a hepatic origin.
Conclusions:
This analysis involving 892
patients treated with 3900–4000 mg/day of APAP shows that83% never had an
ALT>ULRR. Low-level, transient ALT
elevations were reported in 17.8% of patients and usually resolve or decrease
with continued APAP treatment, are unaccompanied by signs or symptoms of liver
injury, and, as such, appear to be clinically insignificant.
No patients treated with the
maximum recommended dose of APAP developed an ALT>3 x ULRR in conjunction
with hyperbilirubinemia. The maximum
recommended daily dose of APAP did not cause liver failure or dysfunction even
when use for 12 months. When used at
recommended doses, APAP remains a safe first-choice treatment for OA.
Table. Number (%) of Osteoarthritis Patients With or
Without an ALT Value >ULRR During Treatment With the Maximum Recommended Daily
Dose of APAP for 4 Weeks to 12 Months
|
|
Total |
Total |
>1.5 × ULRR |
>3 × ULRR |
>5 × ULRR |
>10 × ULRR |
|
n |
733 |
159 |
42 |
10 |
4 |
0 |
S. Maylin; M. Martinot -Peignoux; N. Boyer; M. Ripault;
D. Cazals-Hatem; N. Giuily;
C. Castelnau; C. Féray; M.
Nicolas-Chanoine; P. Bedossa;
P. Marcellin
Background:
It is unclear whether hepatitis C
virus (HCV) is eradicated in patients with chronic hepatitis C who achieve a
sustained virologic response [SVR). During this long-term follow-up study, HCV-RNA
was measured in serum, liver, and peripheral blood mononuclear cells [PBMCs) in patients with chronic hepatitis C who had a SVR
and in whom liver histology was assessed.
Patients/Methods:
345 patients with SVR after
treatment were studied. SVR was defined by the absence of detectable serum
HCV-RNA 6 months after treatment cessation. 242 (70%) patients received PEG-IFN
plus ribavirin therapy (215 PEG-IFN alpha 2b and 27 PEG-IFN alpha 2a). HCV-RNA
was tested: -(1) in serum for all the 345 patients every years and at the time
of PBMCs and/or liver tissue collection, -(2) in PBMCs collected in 159 patients 3.9±3.4 (0.5-18) years
after treatment, -(3) in liver tissue in 116 patients, (32 at the end of
treatment, 32 six months after treatment cessation and 52 at 3.9±3.4 (1-14)
years post treatment. Both PBMCs and liver tissue
were available in 60 patients. Serum, liver tissue samples and PBMCs were kept frozen at -80°C until use. HCV-RNA was
detected with VERSANT HCV-RNA Qualitative assay (Qual
TMA, Bayer Healthcare, LLc, Tarrytown, N.Y. USA)
(sensitivity 10 IU/ml). We assessed the TMA sensitivity using 3 WHO standard
dilutions tested 10 times. 100%, 100% and 60 % of the WHO dilutions set at 5
IU/ml, 2.5 IUml and 1 IU/ml were detected with TMA.
Results:
Patients were followed up for a
mean of 4.0±3.01 (range, 0.5 -18) years. Serum HCV RNA remained undetectable in
all the patients (1624 samples). Normal serum ALT levels were maintained in
most of the patients; HCV-RNA was detectable in the PBMCs
for 2 patient (3 years after treatment cessation), and in the liver tissues for
2 patients, (1 at 1 year; 1 at 6 years). The 2 patients with detectable HCV-RNA
in liver tissue had available PBMCs with undetectable
HCV-RNA. Pre and post-treatment liver biopsy specimens were available for 126
patients. Fibrosis stage was improved in 56%, stable 32% and deteriorated in
12%. Regression of cirrhosis was observed in 9 out of 14 patients. No cirrhosis
decompensation was observed.
Conclusion:
·
These data are some of the longest follow-up data
available (up to 18 years after treatment cessation) in patients successfully
treated fro chronic hepatitis C.
·
None of the 345 patients in this study had a late
relapse
·
210 (98.6%) of 213 patients had undetectable HCV
RNA in PBMCs or liver tissue, determined by the
sensitive TMA assay.
·
These results confirm observations from our earlier
study: clearance of serum HCV RNA is
durable and associated with undetectable hepatic HCV RNA and market histologic improvement.
·
Our data show the importance of using a very
sensitive assay (TMA) to assess SVR.
·
Risk for hepatocellular carcinoma remained in
patients who attain an SVR, underscoring the need for continue surveillance of
this cohort if cirrhosis persists.
·
These results support the hypothesis that HCV is
eradicated in patients who attain an SVR after receiving IFN-based therapy.
C.
Liu; P. Chen; J. Kao; M. Lai; C. Chen; C. Liu; M. Yu; C. Dai; Z. Lin; W. Chuang; S. Lu; J. Wang; T. Hu; C.
Hung; C. Lee; W. Su; S. Wu; C. Lin; L. Liao; H. Kuo; H. Tung; Y. Chao; S. Tung; S. Yang; D. Chen.
Introduction:
Pilot studies using standard interferon in combination with
ribavirin for 6 months to treat patients with dual chronic hepatitis C and B
infection have shown that a sustained hepatitis C virus (HCV) clearance rate
could be achieved to an extent comparable to that observed in HCV monoinfected patients. We have therefore conducted a multicenter clinical trial using peginterferon-based
combination therapy in Taiwan.
Patients and Methods:
Eligible patients with active HCV (serum ALT level >=1.5X
ULN and HCV RNA >=100,000 copies/mL), with (n=161) or without (n=160)
co-existence of hepatitis B surface antigen, were consecutively enrolled.
Patients infected with HCV genotype 1 received 48 weeks of combination therapy
with peginterferon alfa-2a 180 mcg weekly plus daily
1000-1200 mg ribavirin. Patients with HCV genotype non-1 received 24 weeks of
combination therapy with peginterferon alfa-2a 180
mcg weekly plus daily 800 mg ribavirin. The primary efficacy endpoint was
sustained HCV RNA clearance at 24 weeks post-treatment.
Results:
Patients were recruited and enrolled between June 2004 and
end of February 2006. Here we present
the interim results updated in October 2006 (table).
Summary
·
A
sustained HCV clearance rate of 59% was achieved in the most difficult-to-treat
patients with genotype 1 HCV/HBV dual infection, 24 weeks post-treatment
·
In
HCV genotype non-1 dually infected patients, HCV clearance (81%) was achieved
to an extent comparable to that observed in HCV monoinfected
patients (77 % and 79% for genotype 1 and non-1 patients respectively)
·
In
general there was little difference between response rates for genotype 1 and
non-1 patients or at the end of treatment and f24 weeks post-treatment.
Conclusions:
Combination therapy using peginterferon
alfa-2a with ribavirin appears safe for patients dually infected with HCV and
HBV. Final results will be available at
the end of 2007.
Table 1: HCV RNA
clearance at the end of treatment (EOT) and at 24 weeks post-treatment (SVR)
|
|
Dual
Hepatitis B and C |
HCV
monoinfection |
||
|
HCV genotype |
1 |
Non-1 |
1 |
Non-1 |
|
Pts Enrolled (n) |
97 |
64 |
110 |
50 |
|
Pts withdrawn (n/%) |
11 (11.3) |
4 (6.3) |
8 (7.3) |
2 (4.0) |
|
Pts(n/%) Completing treatment/follow-up |
30 (30.9) |
40 (62.5) |
90 (7.3) |
2 (4.0) |
|
HCV EOT response* (%) |
68 |
86 |
87 |
91 |
|
HCV SVR (%) |
62 |
85 |
80 |
81 |